Buckle for wheel traction devices



March 2, 1937. H; s'roKKE BUCKLE FOR WHEEL TRACTION DEVICES -Filed Aug. 14, l19:55

IIIIIIIIIIIIIIIII Patented Mar. 2, 1937 UNITED STATES PATENT OFFICE Harold Stokke, Winona, Minn., assignor to Peerless Chain Company, Winona, Minn., a corporation of Minnesota Application August 14, 1935, Serial No. 36,104

2 Claims.

My present invention provides an extremely simple but highly important improvement in the construction of buckles such, for example, as those used in traction devices applicable to tire- 5 equipped vehicle wheels.

In the accompanying drawing I have illustrated my invention as incorporated in a buckle of the character employed in the pending application of Joseph B. Bambenek, Peter Worner, and myself, Harold Stokke, Serial Number 26,424, led June 13, 1935, and entitled Traction device for tireeequipped wheels. It should be understood, however, that this improved feature of the buckle may be employed or incorporated in l5 buckles of various different designs.

It is a Vwell-known fact that a ribbon, strap, cloth sheet, or the like, may be torn or first broken or disrupted at its edge by a strain that is very much less than that would be required to produce a tear or break by strain applied to the whole or a very considerable portion or, in fact, to any intermediate portion of the article.

The buckle shown in said pending application has been found very efficient for the purposes had in View but is, nevertheless, subject to the following action, to wit: Shackles applied to tireequipped wheels in the manner of the above application, or in any similar manner, will, under continued use, creep circumferentially on the tire until the creeping action is stopped or interrupted by engagement of the strap against a Wheel spoke; and when this happens, the strap will be thrown into an angular position and substantially all or, at any rate, a very great portion of the strain will be applied to one edge of the strap that is clamped between the edge of the tongue and the co-operating cross-bar of the buckle, thus tending to initiate or start a tear of the strap at that edge which is then put under substantially all of the strain.

My invention, by a very simple contrivance or arrangement, causes the tongue and cross-bar of the buckle to primarily and chiefly grip the intermediate portion of the strap, that is, portions of the strap between its oppositeledges, thus relieving the edge of the strap from tearing and cutting strain.

The invention will be more completely and readily understood after having rst described the buckle structure as illustrated in the accompanying drawing, wherein like characters indicate like parts throughout the several views.

Referring to the drawing:

Fig. l is a fragmentary side elevation showing a portion of a tire-equipped Wheel rim and showing one of the improved traction devices including the improved buckle feature applied thereto;

Fig. 2 is a section taken on the line 2--2 of Fig. l;

Fig. 3 is a perspective showing the buckle dis- 5 connected from the shackle;

Fig. 4 is a'detail in section on the line 4--4 of Fig. l;

Fig. 5 is a fragmentary view corresponding to Fig. l but with the wheel omitted, illustrating 10 the action of the buckle; and

Fig. 5a is a fragmentary elevation illustrating a modied form of the buckle.

The structure illustrated in Figs. l to 5, in-

clusive, except for the novel and important for- 15 u' mation of the cross-bar of the yoke, is that illustrated in the pending application above identied, and hence, these parts may be quite briey described.

The numeral 5 indicates the wheel rim and the 20 numeral 6 the pneumatic tire of a tire-equipped wheel such as found on a large number of commercial automobiles, trucks and the like.

Of the parts of the shackle, the numeral I indicates the tread or traction chains (of which 25 as shown there are two), and the numeral 8 indicates the anchoring strap. The permanently connected ends of the chains I and strap 8 may be connected in various different ways so far as the present invention is concerned, but preferably 3o and as shown, they will be permanently but flexibly connected by a coupling made up of links I6 and a coupling yoke I0, which latter has a crossbar IIla that bears against the adjacent side of the tire 6. 35

The buckle, the preferred form of which is illustrated in the drawing, comprises a transverse hinge rod II, a yoke-forming rod, and a buckle tongue I2. The yoke-forming rod is intermediately bent to form a buckle yoke I3 and cou 40 pling loops I 4. This yokefforming rod is rigidly secured to the hinge `rod II preferably by being spot welded thereto at points marked I5 and I5a, so that the hinge rod and yoke-forming rod become practically integral structures. The cou- 45 pling loops I 4 are shown as connected to the otherwise loose ends of the tread chains 1 by links I6.

The buckle tongue will be applied to the coupling rod or bar II before the latter has been 50 welded to the yoke-forming rod. This tongue is preferably stamped from sheet steel and is bent to form laterally spaced hinge lugs II, through perforations in which the intermediate portion of the hinge rod II is passed, so that the tongue is 55 confined for pivotal movementJ between the sides of the buckle yoke I3. The lugs I'I are provided with inturned ears I8 which, as will presently appear, form an abbreviated or incomplete crossbar. The strap-gripping edge of the tongue I2 is extended into close association with the cross portion of the yoke I3 and it is provided with laterally projecting ears I9 that form stops and, as will presently appear, afford ready means for releasing the tongue from the strap when the device is to be removed. The tire contacting end of the tongue, to wit: the shorter end thereof, inwardly is offset considerably from the hinge rod II and extends radially of the wheel when applied outward of said rod II. This is impertant, see particularly Fig. 2, because the arrangement is thereby made such that when the entire tread device is applied to a wheel rim and tire, the said short end, here designated at I2a, will be tightly seated against the adjacent side of thc tire, holding the other portions of the buckle and also the links I6 out of contact with the sides of the tire. Here it may also be noted that the coupling device Illa above briefly noted, is or may be substantially the structure illustrated in Fig. 3, but with the tongue of the buckle omitted, and with the rod Illa engaged against the adjacent side of the tire so as to hold other portions of the coupling and links 9 normally out of contact with the tire.

The manner of applying the anchoring strap 5 through the buckle is probably obvious from inspection of Fig. 2, but it may be stated that in thus applying the strap to the buckle, it is first passed between the cross portion of the yoke I3 and the gripping edge of the tongue I2 and pulled downward until the tread device has been tightly clamped onto the tire, whereupon under pressure applied to the end I2a of the tongue, its gripping edge will be caused to very tightly grip the strap against the cross portion of the yoke; and of course, the greater the tension put on the shackle, the more tightly will the anchoring strap be gripped by the buckle. To further secure the strap against accidental loosening, it is then passed upward over the intermediate portion of the hinge pin II and then brought downward inside of the lugs I8. In this way, the strap is given several abrupt kinks which will insure it against accidental loosening. The anchoring strap 8 may be made of different materials but preferably will be of heavy textile fabric which has such flexibility as to permit its ready appli,- cation in the manner described, but which will be of such stiffness that it will not accidentally loosen the buckle even at points beyond the place where it is directly gripped between the tongue and yoke, at which latter point, however, the strap is constantly held under a gripping action that is proportioned to the tension at which the shackle is held on the rim and tire.

Attention is now directed particularly to Fig. 5, wherein the strap is illustrated as pulled laterally out of straight line as will happen when the traction device has creeped on the tire as far as permitted by the adjacent wheel spoke.

It is now important to note that the cross-bar of the buckle yoke I3 is inwardly bowed at its central portion so that the strap 8 will be primarily gripped at its transversely central portion between the transversely central portion of the buckle tongue I2 and the point I2a of said crossbar. At the points I2b there will be primarily little or no gripping action between the tongue and the yoke, but between the points I2a and I2b the gripping action on the strap will be progressively outward toward the points I2b. It follows from this action that the greatest gripping action will always be at the transversely central portion of the strap and the edges of the strap will be free from that gripping and tearing action which hitherto has iii the course of time and continued use resulted in cutting the strap progressively from its edge toward the intermediate portion of the strap. 'I'his gripping action results from a structure which, on its face, may appear as a slight modification of the older form but which, in practice, has been found to make the difference between a structure which will cut the straps and shorten the life of the device and a device that will not cut the straps and will render the straps useful for a relatively Very long time.

What is thought to be the best form of the device is illustrated in Fig. 5 but a useful modification thereof is also illustrated in Fig. 5a. In this modified structure the cross-bar of the yoke I3 is straight and the co-operating edge of the tongue I2 is bulged or rounded at l2". With either of the structures illustrated the chief biting action of the buckle elements on the strap is at the transversely central portion of the strap and the edges of the strap are primarily left free or' substantially free from gripping action so that even when the strap is pulled at an angle, the full strength of the strap is rendered available to resist pull or tension and there will be no biting or cutting action at the edges of the strap.

It will be understood that a buckle of the above character has particular application to and is especially important when used in a traction device which is subject to creeping action on the tire and which produces the above tendency to cut the strap from its edge inward.

What I claim is:

l. A strap-engaging buckle comprising a yoke and a relatively movable co-operating tongue, one of said members having a strap-engaging surface bulged toward and opposed to the strap-engaging surface of the co-operating buckle member, whereby the strap will be engaged with a maximum gripping action at its transversely intermediate portion, said tongue extending obliquely through said yoke between the ends thereof, and means mounting said tongue on said yoke at elevated points remote from the bulged strap engaging surface of the buckle and causing the free end portion of the strap to retain the tongue in gripping position.

2. A strap-engaging buckle comprising a yoke and a pivotally associated tongue, the transverse outer end portion of said yoke being bulged toward and opposed to the strap-engaging edge of said tongue, whereby, the strap will be engaged with a maximum gripping action at its transversely intermediate portion, said tongue extending through said yoke from a point above the bulged end portion of the yoke to a point below the opposite end of the yoke, and means mounting said tongue on said yoke at points intermediate its ends and causing the free end portion of the strap to retain the tongue in gripping position.

HAROLD STOKKE. 

